Since Erikson's original formulation(1959), the concept of identity has influenced not only the psychology of adolescence but a broad range of disciplines in the social sciences and humanities as well. This influence has extended even to ordinary language, contribution such common expressions as "finding one's identity" and "identity crisis". In the past 15 years approximately 50 empirical studies have sought in various ways to operationalize the concept of identity and investigate its personality and behavioral correlates. In recent years empirical research on ego identity has been dominated by James Marcia's concept of "identity statuses"(1964, 1966). In Korea, considerable research on ego identity has appeared over the past 9 years. Nearly all of these studies including Korean's have proceeded on the basis of a particular formulation of Erikson's concept. Empirical researches on ego identity were discussed and evaluated according to the following three standpoints in this review : 1) The measurement of ego identity, 2) The relation between Identity Status and other areas, and 3) The long-term stability of the identity statuses. In the first section, the different procedures which have been used to measure ego identity, were summarized, such as Q-sort and self-report questionnaires measures, In the second section, studies were ordered according to a number of topical areas which highlight some of the more important findings that have come out of this research tradition to date, in relation to Marcia's Identity Status(i.e., achievement, Moratorium, foreclosure, diffusion). Briefly, these included intelligence, cognitive performance and antecedents, college adjustment, interpersonal relation and intimacy, sex differences and so on. The third section was about the long-term stability of the identity statuses. Some studies indicate that and individual's identity status assignment at one time does not readily predict his identity status several years later. In this research, some suggestions for future research were suggested. At first, most of the researches on ego identity have taken the college students as subjects. From now on any other population such as the high school student, working youth should be taken as subjects in order to generalize broadly the existing research findings. Secondly, the original step of categorizing the broad construct of identity into subtypes, each of which is subsequently evaluated by interview rather than questionnair, seem to have had a broad appeal to investigators. But the Identity Status Interview does not capture all Erikson had in mind, rather it strikes an optimal compromise between Erikson's clinical idiographic form of inquiry and that prescribed by nomothetic, empirical science. Still more crucial, however, is the question of the overall validity of Marcia's paradigm as a theoretical and empirical approach to the study of ego identity. Therefore, the identity status interview approach remains open to a number of methodological improvements. Thirdly, in this research it has been suggested that ego identity be investigated not only as a static configuration but also in terms of developmental processes which contribute to the individual's acquisition of a "sense of who he is". It is important to add that "identity" cannot properly by understood as a developmental end-point. Rather, it must be assumed that processes mediating both identity consolidation continue beyond adolescence and throughout adulthood as the individual reponds to crisis in his life situation. Finally, though research on ego identity has increased considerably since 1970, the area is still relatively new in comparison with many other areas of adolescent developmental research. To sum up this study, two possible directions for future research are suggested. On one hand, considerable work remains to be done within the identity status paradigm. On the other, the study of both identity as process and of the variables mediating identity formation indicates a new point of departure for research requiring the development typological approach.